Free light chains (serum)

 

Alternative names, keywords

Kappa, lambda, FLC, SFLC

Samples required

● Clotted blood (gold cap, 5 mL tube).

Test indications

For the investigation of possible paraproteinaemia, which can be present in multiple myeloma, lymphoma, Waldenstrom macroglobulinaemia etc.

Please request serum free light chains WITH serum protein electrophoresis for a full paraprotein screen.

Test information

Restrictions are in place for this test to prevent inappropriate repeat requesting. See minimum requesting intervals for more information and downloadable override form.

Reference range
   
Kappa free light chain (mg/L)
Lambda free light chain (mg/L)
Serum free light chain ratio
 eGFR ≥60:

 less than 70 years

6.3 - 39.0

5.9 - 36.7

0.44 - 2.16

70 years and above

7.0 - 55.8

6.4 - 48.0

0.46 - 2.59

eGFR 45 - 59*

7.8 - 83.6

7.3 - 65.1

less than 70 years: 0.44 - 2.16

70 years and above: 0.46 - 2.59

eGFR 30 - 44*

8.8 - 103.3

8.2 - 73.2

eGFR less than 30*

11.7 - 265.1

12.6 - 150.9
* eGFR-specific reference ranges for kappa and lambda may not be specified on the report. The reference ranges for the ratio do not change based on eGFR.

Note new reference ranges from 1 July 2026

For MGUS monitoring see the locally commissioned service (LCS) for primary care.

Turnaround time

2 working days

Enquiries

Biochemistry (Special Chemistry)

 

Details